1. Field of the Invention
The present invention relates to a cantilever type probe head, and more particularly to a cantilever type probe head having conical columns, in order that when the probe head contacts a pad of a member to be probed, a better effect of indication in contacting and guiding can be attained, the probe head suits measuring of a high frequency integrated circuit or some other electronic element.
2. Description of the Prior Art
There have been various probe assemblies for measuring integrated circuits or micro electronic elements, wherein a representative assembly uses an electric circuit card, its upper side is formed elongate conductor traces used as signal and grounding lines, the card is formed thereon a central opening, the tips of probes are attached to the ends of the signal traces near by the opening, thereby the probes are aligned radially and pointing downwards, in order to be optionally connected by a pad of a micro electronic element to be tested.
Recently, electronic circuits are equipped in large amounts with IC's, according to strengthening in functions, increasing of amount and reducing of volume of the products, number of pins of the IC's is increased and gathered, this renders the test after processing of manufacturing more complicated, thereby probes used presently has insufficiency in structural designing, such as are stated below:
1. The contact surface of a probe “A” used presently with a pad is designed rectangular or circular with one end of it tapered (as shown in FIGS. 1 and 1a), if the pad is oxidized to form an oxidized layer, the probe shall be pressed with a large force to pierce the oxidized layer, this often will destroy the pad inadvertently.
2. Design of a rectangular or circular contact surface “B” is almost same in shape as that printed on the pad, so that when in measuring, the contact surface “B” of the probe forms a parallel surface in opposition to that of the pad, thereby a user is uneasy to assure whether the probe “A” is aligned or contacted with the pad.
3. When the rectangular or circular contact surface “B” is worn away after using for a period of time, the contact surface will deform, and even the area of the contact surface “B” of the probe “A” will be getting larger and be unable to pierce the oxidized layer of the pad for electric connecting, thus the entire probe “A” must be changed.
In view of the above stated, the inventor provides the present invention after study, development and improvement.